Police in Paris have shot and injured a man who tried to attack an officer outside Notre Dame cathedral.

BFMTV and other French media reported that the attempted attack involved a hammer. Witnesses said four plainclothes police officers, doctors and paramedics could be seen surrounding the suspected attacker, whose condition is not known.

David Rahul Métreaum, a witness, told BFMTV that he could see a “man on the ground who is not moving”.

“There is a group of people from the emergency services around the man on the ground.”

Police asked people to stay away from the area, which has been evacuated. Large numbers of police cars filled the area on the Île de la Cité island in the river Seine in the centre of Paris.

The French prosecutor’s office said the counter-terrorism office has opened an investigation.